(1) Field of the Invention
The present invention relates to model management system and apparatus, and more particularly, to a system and apparatus for managing two- or three-dimensional models.
(2) Description of the Related Art
With recent advance in three-dimensional CAD (Computer Aided Design), there has been an increasing tendency to produce necessary drawings, parts lists, etc. from three-dimensional product models created beforehand on a computer.
Simultaneously, PDM (Product Data Management) has also been spreading in which all data relating to product development is managed in an integrated manner for effective use of data and higher efficiency of design work etc.
Recently, therefore, there is a growing tendency to harmonize three-dimensional CAD with PDM, thereby to make more practical use of data through the course of process from design to manufacture.
In a system wherein three-dimensional CAD is integrated with PDM, usually data is collected after the completion of design at a predetermined server for centralized management. However, bulk data, which is actual data of a model created by three-dimensional CAD or the like, has a vast amount of information (e.g., several gigabytes), and if such massive data is transmitted, a problem arises in that the load on the network increases.
Also, it is occasionally necessary that a created three-dimensional model be output in the form of a two-dimensional drawing to a display device or on printing paper. In such cases, with conventional systems, data such as attributes must be acquired by manual operation from parts lists which are under the management of PDM and be inserted into part columns of the drawing, and also authors' names must be acquired from the parts lists and inserted into title columns, thus giving rise to a problem of complexity. Also, in cases where correction has been made to a model, a problem arises in that such correction is not reflected in the drawing.
Conventionally, moreover, a version number of a model is set at the time when the model is approved after the completion of design. When designing a product, the product is redesigned again and again depending on the level of trial manufacture or according to the destination of product, but since the version number is set without regard to the level of trial manufacture or the destination, a problem arises in that it is difficult to judge solely by the version number up to which level of trial manufacture or for which destination data has been refined.
Further, in the stage of design, a plurality of alternative parts are sometimes prepared beforehand so that a regular part may be selected from among the alternative parts in accordance with the results of trial manufacture or simulation. Conventionally, where there are a plurality of alternatives for a certain part which constitutes a model in combination with another part, it is usually the case that a plurality of models equal in number to possible combinations are generated. For example, in the case where a model is constituted by parts A and B and the part B has an alternative part B′, two types of model, (A+B) and (A+B′), are generated and registered. Accordingly, if the number of alternative parts is large, the number of combinations of parts correspondingly increases, making the management of models complicated and also entailing an increase in the amount of data.
Furthermore, in cases where multiple designers take part in design work, data is generally managed by exclusive control so that identical data may not be modified simultaneously. However, parts constituting a model are related with each other, and thus when a certain part has been modified, it is often necessary that the parts related therewith should also be modified. Conventionally, the exclusive control is performed only on identical parts, and therefore, in the case where one of the related parts has been modified, there is no measure to notify other designers in charge of design of the other parts that the part has been modified, possibly making the other designers' work useless.